Endometrial cancer staging-Federation Internationale Gynecology and Obstetrics (FIGO)
Stage IA Tumor limited to the endometrium
Stage IB Invasion <50% of the myometrium
Stage IC Invasion ≥50% myometrium
Stage IIA Endocervical glandular involvement only
Stage IIB Cervical stromal invasion
Stage IIIA Tumor invading serosa of corpus uteri and/or adnexa and/ or positive cytology
Stage IIIB Vaginal metastases
Stage IIIC Metastases to pelvic and/or paraaortic lymph nodes
Stage IVA Tumor invasion of the bladder and/or bowel mucosa
Stage IVB Distant metastases, including intraabdominal metastases and or metastases to inguinal nodes
Endometrial cancer staging is currently defined by the 2023 FIGO system, which uses histopathologic and molecular criteria to more precisely categorize tumor extent and risk. The stages range from I (cancer confined to the uterus) to IV (cancer spread to distant organs), helping guide prognosis and treatment decisions.
## Staging Overview
Stage I-Cancer is confined to the uterine corpus (body of uterus), possibly including the ovary if criteria are met. IA- Disease limited to endometrium or <50% myometrial invasion and non-aggressive histology. IA1-Non-aggressive tumor in an endometrial polyp or just within endometrium. IA2-Non-aggressive tumor with <50% myometrial invasion. IA3-Low-grade endometrioid carcinoma limited to uterus or ovary. IB-Non-aggressive type, >50% myometrial invasion. IC-Aggressive subtypes confined to a polyp or endometrium Stage II-Cancer invades the cervical stroma but lacks extrauterine spread.May include substantial lymphovascular invasion (LVSI) or aggressive histologies with any myometrial involvement[1][3]. Stage III-Regional spread to serosa of uterus, adnexa (ovary/fallopian tube), vagina, parametria, pelvis, or lymph nodes Stage IV-Cancer extends to bladder or bowel mucosa or shows distant metastases (lungs, liver, bones, or beyond abdominal/pelvic area)
The staging now incorporates not just anatomical extent, but also tumor grade, depth of myometrial invasion, lymphovascular space invasion, cervical involvement, lymph node status, and molecular features (e.g., POLE mutations, mismatch repair deficiency, p53 status).
Both FIGO and AJCC TNMsystems use primary tumor (T), regional node involvement (N), and distant metastasis (M) to assign a formal stage, which is grouped to provide a simple stage designation: I–IV
The updated 2023 FIGO system places a growing emphasis on molecular profiling to fine-tune staging and management, especially in high-grade cases